Low Dimensional Metal Halide Perovskites for Optoelectronics

Abstract

Low-dimensional metal halide perovskites possess diverse material properties, offering opportunities for versatile optoelectronic and energy applications.

The first part of the thesis demonstrates a one-dimensional perovskite hybrid plasmonic nanolaser, that integrates a birefringent perovskite nanowire onto a metal substrate separated by a Ta2O5 buffer layer. This configuration exhibits unconventional polarization dependence due to enhanced electric field confinement at the nanowire-buffer interface with orthogonal polarized pumping. Also, strong exciton-polariton interaction induces pronounced emission blueshift under orthogonal excitation. Findings on enhanced optical nonlinearity and unusual anisotropy offer pathways for new designs of polarization-sensitive photonic circuits.

The second part of the thesis develops a revised Material Circularity Indicator (rMCI), which accounts for temporal changes in PV demand for evaluating the circularity of large-scale photovoltaics (PV) deployment. A new Energy Circularity Indicator (ECI) is also introduced. Applying these indicators to different scenarios reveals that strategies favoring ECI are not always optimal for rMCI, highlighting the importance of achieving circular economy from more than one perspective, especially for PV modules. Preliminary calculations point to the benefit of multi-junction tandem solar cell technology, necessitating the development of high bandgap semiconductor materials.

Therefore, the last part investigates two-dimensional halide perovskites to achieve wide bandgap (>2 eV) without halide mixing. The ACI perovskite developed also eliminates the reliance on volatile ammonium-free for stability. Perovskite formation is elucidated to be highly sensitive to cation stoichiometric ratio. Post optimization, devices demonstrated in this thesis produced a champion efficiency and maximum power point tracking stability that outperformed reported >2 eV n=2 layered perovskite solar cells at the time.